Paper-making machine



T H SAVERY PAPER MAKING MACHINE.

(Application filed Nov. 14, 1896.)

(No Model.)

PATENT FFlCEt THOMAS H. SAVERY, or WILMINGTON, DELAWARE.

PAPER-MAKING MACHINE.

SPECIFICATION forming part of Letters Patent No. 611,420, dated September 27, 1898. Application filed November 14,1896. Serial no. 612,098. (No model.)

To all whom it may concern.-

Be it known that I, THOMAS H. SAVERY, a citizen of the United States, residing at Willnington, county of New Castle, and State of Delaware, have invented certain new and useful Improvements in Paper-Making Machines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

In paper-making machines the stock or stuff out of which paper is to be made is necessarily accompanied during a part of the operation of forming it into paper by a large quantity of water, which after performing its function must be discharged therefrom in order that the paper-forming operation may be completed. At different stages of this operation of forming the stock or stuff into paper water is expressed from it by means of moving cylindrical surfaces, between which such stock or stuff or the partially-formed paper is passed and pressed while moving onward. This water thus discharged enters into the angular space or re cess existing at the entrance side of these cylindrical surfaces in front of their nippingpoints, and with the exception of its excess portion, which flows away by being backed up or by gravity, such water accumulates and is maintained in said space or recess by the holding action exerted by the devices operating upon the stuff or stock or in connection with it or its traveling support or carrier, and this water expressed from the paper stuff or stock or its carrier and present in this space or recess is enabled to reenter the paper stuff or stock or its traveling support or carrying device during the paper-formin g operation at times when the removal of water is an essential thing. This angular spaceor recess exists between the forming-felt and the couchroll in a cylinder paper-making machine, between the forming-wire and the couch-rolls in a Fourdrinier paper-making machine, and

between the carrying-felt and the press-rolls in all paper-makin g machines and would exist between two press-rolls if the carrying-felt were omitted. The existence of a body of waterin such angular spaces or recesses and its being absorbed or taken up therefrom operates inj uriousl y in various ways in the paperforming operation. Byrecntering the stock,

stuff, or forming paper it acts to stain parts of the paper to such an extent that a practically perfect product, so essential in this art, is not obtained. By rewetting the stock, stuff, or

forming paper or the carrier thereof it necessitates more extended operations in producing paper. By accumulating impure or injurious matter it not only imparts the same to the stock, stufi, or forming-paper carrying devices, soon rendering them inoperative, but

enables them to impart such impurities to the stock or stuff undergoing formation into paper.

The invention therefore has for its object the rapid and constant removal of this injurious water; and it consists in providing this angular space or recess in front of or at the entrance side of said cylindrical surfaces, between which latter the layer or web of paper stock or stuff or the unfinished paper is during its different stages of formation carried and pressed, with means for not only discharging the water from the recess at the entrance side of or in front of the nipping-point of one or more coacting sets of such cylindrical surfaces, but keeping said recess free from such water by preventing its accumulation therein, so that water once expelled from the stuif or stock undergoing formation into paper may not return to the stock, stuff, or forming paper or to the carrying devices or traveling support thereof or convey impurities into the forming paper or to the stock or stuif carrying devices, as the wire apron or a felt, by which, especially a felt, such impurities would be taken up, retained, and given off to the stock or stuff or become embodied with the felts to such an extent as to require their frequent washing and stopping the machine for that purpose.

Some of the advantageous results oonsequent upon the use of this invention are the enabling of the stock or stuff to be worked drier, and hence formed more speedily into paper, a diminution of the loss of paper due to stained portions or breaking of the web, and the making of more paper in a given time,because it renders breaking of the stock, stuff, or paper and stoppage of the machine less frequent.

In the particular form herein especially used as the illustrative example of the em bodiment of this invention the said means consist of a water conductor or plate that so coacts with the said recess, preferably by entering into or tapping the same, that it operates to liberate and convey said body of water therefrom.

A practical embodiment of this invention as embraced in conductor form is illustrated in the accompanying drawings by so much of a Fourdrinier paper-machine as is necessary to an understanding of the invention.

Figure 1 illustrates a diagrammatic side elevation of that portion of a Fourdrinier paper-machine, intermediate its ends, to which this improvement is applicable in connection with its couch and first and second press-rolls; but this figure particularly shows the practical machine now existing in the art devoid of this improvement and exhibits the defective operations which the said invention obviates. Fig. 2 is an enlarged side elevation of the couch-rolls detached from the machine and having one form of this invention applied to them. Fig. 3 is a similar view of one set of the press-rolls detached from the machine and having another form of this invention applied to them, and Fig. 4 is a similar view of another set of the press-rolls detached from the machine and having a further modified form of said invention applied to them.

To aid a ready understanding of this invention, an explanation of it will be given in connection with the machine illustrated in Fig. 1, as well as its relation to the mechanisms shown detached in the other figures.

In the making of paper large quantities of water are necessarily used. The fibrous material is surcharged with water to float the same over and upon the wire apron 1, so as to enable its formation into a web thereon, and while this body of fibrous stock or stuff is being interlaced to form it into a web on said wire while traveling onward, supported thereby through agitation imparted to it by the lateral shaking of the wire apron, it parts with much of its Water, which as it is liberated descends through the wire into a vat beneath for removal. In passing the suctionboxes, one, 0, of which is shown, this web of fibers is denuded of more of its water, but remains a thick endless saturated body or web a, having'cohesion enough to enable it to be made into paper by removing its remaining water through pressure and by drying. For this purpose this saturated body or web of interlaced fibers is first given greater cohesion and strength by the action of the cylindrical surfaces or couch-rolls 2 9, between whichit is led directly from the wire 1 and by which it is compressed to partially consolidate its body, during which action a large proportion of the water it still contains is expelled. It is thus given the condition and substance of a wet web, which must be again pressed and dried to constitute it finished paper. At the nip of these couch-rolls,

v through which the wire 1 supportsand carries the saturated web in its passage through the machine, (said wire returning about the lower couch-roll,) a large quantity of water is constantly pressed out of the forming paper and passes through the wire into the recess formed between said wire and the upper side of the lower couch-roll. This body of water as its quantity sufficiently accumulates constantly loses a certain excess, which descends by gravity into the vat beneath the said wire and couch-rolls; but a quantity thereof is as constantly held in this recess (see rolls 2 9, Fig. 1) by the action of the onwardly-moving wet web with its natural affinity therefor or by the frictional action of the onwafdly-moving surface of the lower couch-roll or by the action of the attractive force of the globules of water contained in the interstices of the wire or by two or all of them, and the consequence is that this body of water will not only resist the action of gravity and remain in said recess, but it will continuously accumulate dirt or other matter injurious to the paper when finished and will convey the same to the forming paper.

The body of water thus constantly maintained in this recess acts to as constantly return moisture once removed therefrom to the then wet paper stock or stuff, and thus increases the operations necessary to make it into a finished or dry paper or acts to so diminish the effectiveness of those employed as to require an increase of the drying devices. To avoid these injurious and modifying defects, the couch-rolls are by the present invention provided with a water-conductor, as illustrated in Fig. 2, the structure of which is preferably a metal plate A, the shape of which is such that its forward portion or end will penetrate into the recess where this in j uriously-acting body of water is first received and would otherwise be maintained, which conductor or plate so operates as to liberate the water from the influences holding it there that it readily moves out of the recess, passes immediately away from the wire, the web, paper stock or stuff it carries, and the couch-rolls and is discharged from the machine. This action continuously takes place, with the result that the Water is rapidly discharged from said recess as it is received therein from the wet web of stock or stuff and its carrying-wire, so that neither rewetting of said paper stock or stuff nor its wire can take place, the dirt or impurities accompanying such water may not become added to such stock or wire to injure the forming paper, and less water will be carried onward in the machine beyond the couchrolls to impose its removal upon subsequently operating mechanisms, and the web is rendered drier and'stronger at this point than it would otherwise be. There are many constructions in which this water-conductor may be embodied, the one shown in Fig. 2 being a metal sheet having a forward end made to generally conform to the curvature of the front or breast of the lower couch-roll and provided with an uninterrupted rearward end bent to Conveniently lead the water from said recess and discharge it into the vat beneath these rolls and wire. As it emerges from the couch-rolls 2 9 this partially-pressed but still wet web a (shown by dotted lines) is stripped from the wire and directed thence to a felt or apron 8, which constitutes a traveling support, by and with which it is carried to and through the first press-rolls 4 10, between which cylindrical surfaces it is again pressed to expel from it a large portion of the water remaining in it, and whereby it is made a still drier and stronger web. From these first press-rolls the pulp web, Well compressed and largely rid of water, but usually still so wet as to require another pressing operation, is carried onward through a considerable distance exposed to the air by means of this endless felt 3, and is thence lifted therefrom, guided over leading-rollers, and directed to the surface of a second felt 5, on top of and with which it is carried through the second pressrolls or cylindrical surfaces 6 ll. In passing the nip of these rolls it is subjected to what is usually the final pressing operation, and by which substantially all of the water remaining in it is expelled, so that it then becomes a completed paper web, which, being damp, only requires to be dried to complete its condition. For this purpose such damp web of paper is led from the felt 5 and con veyed to the driers, which are interiorlyheated cylinders, one, 7 only of which is shown, in contact with the surface of which the damp paper web is held and carried by the drier-felt 8, as is indicated by the dotted lines. Other finishing operations are then performed upon it, if desired, such as calendering its surface, cutting it into sheets, or wind ing it into rolls. The still wet web when it arrives at the nip of the first press-rolls 4 10 will be pressed thereby and much additional water will be expressed therefrom, as this is a pressing operation much greater than that of the couch-rolls and is applied to substantially consolidate said web and more nearly convert it into paper, and when pressed by the second press-rolls a more powerful pres sure may be applied for the reason that but little water then remains which can be expressed, and this operation finishes the product except to dry out the dampness it retains. These first press-rolls, as well as the second press-rolls, are usually set on axes which are relatively vertically arranged, and hence the water-holding recess formed between them outwardly from their nipping-point in the direction from which the paper web is received by them furnishes a more nearly horizontal base to act in aid of the support and retention of the injurious body of water that enters this recess between the rolls as it is pressed out of the web and passes through the felt 3 into said recess, from which disposition of these rolls its retention there tends to be readily effected by the onward movement of the rolls and that of the felt, and from which recess the effect of gravity thus modified will not remove more of it than the excess quantity which accumulates at or beyond the outer face of the lower roll, as is seen in Fig. 1, in connection with both sets of these press-rolls. These press-rolls are provided with a highly-polished surface for contact with the web, and the excess water discharged over them is sometimes stripped from their surface by a doctor-plate, which not only cleans them by removing from them the excess water thatiiows over the outer front side of the lower roll, but directs the water into their vats; but these doctors have no effect upon the water retained in said recess, because such water is held there by other causes not affected by the doctor. To efficiently remove the injurious body of water held in the recess at the front of these pressrolls and keep the recess clear, there is applied to them the water conductor, constructed preferably as shown in Fig. 3, which consists, as before explained, preferably of a metal plate curved to conform to the arc of the roll to which it is applied with its forward surface entered into said recess, it may be, quite closely to the nip of the press-rolls and provide its rear end with a trough B, from which the accumulating water may be removed in any convenient way. When the forward end or edge of this conductor is so entered into the said recess between press-rolls, the body of water otherwise constantly retained in contact with the press-roll and felt, and thus enabled to so act as to greatly modify the paper-making operation and injuriously affect the quality of the paper, is-surely removed from or drained out of said recess and discharged from the machine by the trough B and a pipe or other similar means that may be provided, thus keeping said recess clear and ridding the paper-making machine, as heretofore constructed, from the faulty action and injurious effects produced by the accumulation and retention of the water between these press-rolls.

In Fig. 4 another modification of this waterconductor is shown, which for convenience is in this instance shown as applied tothe second press-rolls. Here it is illustrated as having a forward member or conductor A, which is a curved plate suiting the general curvature of the lower press-roll 11, which plate is supplemented with a top D, bottom 0, and rearward member E, and is to have two ends (not shown) whereby it is converted into a box which is provided with a long receiving-orifice that may protrude into said recess, which structure, while enabling the water that is to be removed to freely enterinto it, will prevent the water, if in a foamy condition or agitated through any cause, from splashing against the rolls, wire, or felt. This box will of course be supplied with a pipe, as P, through'which the water it re sion thereto to any active extent and where-- by the onward driving efiect thereof is avoided, and as this conductor presents a smooth supporting guiding-surface for the water gravity will immediately act to cause its backward fiow out of this recess so quickly that it will not accumulate in quantity sufficient to again reach the wire or felt through which it flowed, and hence cannot adhere thereto to modify this action or pass through the same and reenter the paper stock or stuff from which it was derived. In other words, this water is thus given a new and quiescent basic support that is independent of the surface of the roll and isolated from the onward driving force thereof, and such water is thus brought within the active discharging force of gravity alone and is thereby enabled to rapidly flow out of said recess, and the same is kept free and clear from injurious water or deleterious matter contained therein.

Concerning the damaging effect of water made use of in the production of paper it is to be noted that where water, even though it be pure, is allowed to soak into a paper web by moving backward into the same after it has been expelled therefrom it has the effect to impart to the web stains that present irregular bounds or form waved lines which are the limits to which this returning water extends before it is so far absorbed as to cease its movement. These stains are readily perceived in the finished paper and cause the sections of the web containing them to be useless, which damaging action of the water, pure or impure, is prevented by this invention.

Another and important beneficial effect is produced by this improvement upon the endless felts, which in order to operate to the best advantage in forming the paper web are made wider than the press rolls are long, whence it follows since their edges projecting beyond such rolls are not clamped between the rolls, but on the contrary are free, that they are in the best condition to readily absorb water if the same is present in said recess between the press-rolls. The result is when water is present there and the edges of the felt become charged with it they not only carry the water onward and flirt it over the machine, but in consequence of such wet edges being in contact with the paper web after it has passed the press-rolls they give off the water they carry to the edges of the paper and thus impregnate the otherwise drier body of the web with water, so that the pressing and drying thereof must be great enough for the treatment of the wet edges, or, otherwise stated, in excess of what is required for the body portion.

It is to be noted that while the curved form of the conductor is not essential it is advantageous, because it leaves the said recess as free from obstruction as is possible and thus affords the largest waterway.

It may now be said that this invention is applicable generally in either of the forms shown not only to couch-rolls but to' as many press-rolls as may require it or it is found desirable to equip with it, 'according to the quality or thickness of paper being made.

By means of this invention a high speed of production may be attained, as the paper is stronger because drier at all stages of its formation, larger couch and press rolls may be employed, the number of sets of press-rolls may be reduced, and a less extent of dryingsurface be required or less heat needed to accomplish the drying operation.

In consequence of the fact that this conductor prevents the return of practically all water that is once removed from the stock and the wire or felt carrying the same, with the advantages already stated, it also results in causing the forming paper to be made drier in the earlier stages of and throughout its formation, and therefore enables its course of travel to be lessened and permits of a reduction of the great length in which these machines are now constructed.

The application of these improvements to a paper-machine enables stronger paper to be made, because being formed drier it does not-require to be heated so much and injured thereby. It enables more paper to be made in a given time, because in the web state it is drier, and hence not so liable to break and make waste. It saves the felt of the driers from injury, because a lower degree of heat may be used, and the paper when led to them not being so wet as when made bya machine without this improvement there is less wetting and consequent drying of said felts, which rotsthem. It improves the quality of the paper by running faster, because there is less water to take out of it during the greater portion of its formation, and by its action it keeps impurities from entering the felts and thus soiling them, so that they require frequent washing, which is detrimental in that felts frequently Washed are thereby worn out and rendered useless, and it prevents the edges of the press-felts from receiving water and carrying it into the borders of the paper beyond the rolls.

In some cases the stock or stuff undergoing formation into paper may be so far freed from water as it leaves the couch or first press rolls that it can be led to and passed through the first or second press-rolls without the aid of a carrying-felt, in the absence of which felt this invention will coact with the web of stock or stuff and a press-roll and operate to almost completely remove its remaining dampness, and such an arrangement is therefore comprehended by this invention.

Although the precise structure of this invention herein used for its exemplification has been described as a conductor or plate of IIO scope of my invention.

metal, it is to be understood that any mate rial suitable for its construction and capable of performing its function may be adoptedsuch, for instance, as hard rubber, oil-cloth, and the like sufficiently stiff, strong, and durable material-and where the material used is very hard, as some metals, it is desirable to provide the front end of the conduc-.

tor with a lip-piece of rubber, leather, oilcloth, or the like, so that it may bear upon the roll and make a close joint therewith without marring said roll.

I believe myself to be the first to combine with the recess at the entrance side of the cylindrical surfaces between which the stock or stuff of a paper-making machine is carried and from which the water is discharged into said recess means cooperating with said recess to remove the water therefrom. It is therefore to be understood that means cooperating with said recess to remove the water therefrom may vary from those hereinbefore described and shown and yet be within the What is claimed is- 1. In a paper-making machine, the combination with cylindrical surfaces between which wet stock is carried and from which stock liquid is discharged by the action of the said surfaces into the recess between them, of means extending into the recess between the rolls sufficiently far to tap the space in which the liquid may accumulate, whereby the liquid is drawn off from the said space, substantially as described.

2. In a paper-making machine, thecombination witha traveling support, of cylindrical surfaces between which wet stock is carried by the said support and from which stock liquid is discharged by the action, of the said surfaces into the recess between them, and means extending into the recess between the rolls sufficiently to tap the space in which the liquid may accumulate, whereby the liquid is drawn off from the said space, substantially as described.

3. The combination with cylindrical surfaces between which wet stock is passed to express therefrom the liquid which it contains, of a conductor extending into the recess on the entrance side of the surfaces sufficiently far to tap the space in which the liquid may accumulate whereby the liquid is drawn off from the said space, substantially as described.

4. The combination with a traveling support, of unbroken cylindrical surfaces between which wet stock is carried by the traveling support in order to express the liquid therefrom, and .a conductor extending into.

the recess sufiiciently far to tap the space in which the liquid may accumulate and operating to convey or remove the liquid therefrom, substantially as described.

5. The combination with a traveling support, of cylindrical surfaces between which wet stock is carried by the support in order to express the liquid therefrom, and a conductor consisting of a plate extending into the recess at the entrance side of the said surfaces sufficiently far to tap the space in which the liquid may accumulate and operating to convey the liquid therefrom, substantially as described.

6. In a paper-making machine the combi nation with a traveling support, of cylindrical surfaces between which the stock or stuff is carried by the traveling support and from which water is discharged into the recess at the entrance side of said surfaces, and'a conductor consisting of a plate curved to span a part of the roll and enter its front edge into said recess to discharge the water therefrom, substantially as described.

7. In a paper-making machine, the combination with cylindrical surfaces between which the stock or stuff is passed to express liquid it contains, and from which stock or stuffsuch liquid is discharged into a recess at the entrance side of said surfaces, of a conductor consisting of plates forming a box-like structure open at its forward end the front plate whereof is entered into said recess, substantially as described.

8. In a papenmaking machine, the combination with a traveling suppor-t,of cylindrical surfaces between which the stock or stuff is THOMAS H. SAVERY.

Witnesses:

S. WINTHAL, J. J. KENNEDY. I

ICC 

